Description : The most productive ecosystem in the biosphere is – (1) Desert (2) Open Ocean (3) Estuary (4) Tundra
Last Answer : (3) Estuary Explanation: Ecotone regions (transitional zones) like mangroves, wetlands, estuaries, grasslands etc. have far greater productivity compared to natural ecosystems like forest ecosystem, ocean ... world, with about 60% of the world's population living along estuaries and the coast.